It isn't that's it's poorly implemented. It's a bug. All software has bugs. It just depends on what the bug is. Most bugs rarely cause problems, while some will crash the machine. This is a case where the drive controller firmware, for some reason Samsung hasn't yet found, causes a zeroing out of some, but not all, 512b blocks. This will result in some, but not most, data becoming corrupted.The problem is that for most consumers, they won't know about this data corruption...

That's why I use OWC drives. They are more efficient in garbage collection. They have been specifically made to work well with OS X. Other drives are more generic. I have been using them for years and haven't experienced any slowdowns, as I had with several others.Trim us helpful, but not required.

Just make sure you aren't using a Samsung 8xx series drive when enabling trim. All of those will lose data from trim at some point. There are some other drives that will have this problem as well.
https://blog.algolia.com/when-solid-state-drives-are-not-that-solid/

Don't get too excited about that yet. Trim isn't required for SSDs, though it helps.The reason why Apple hasn't released it for all drives as a standard feature is because of data corruption for a number of popular SSDs. For example, all Samsung SSDs that begin in an "8" will have data corruption after some time when using trim. Some of their enterprise drives have the problem.There are some other drives with this problem.This is why Apple warns that data corruption may...